Microsoft utilise the other 20% for its own purposes.
To use all the bandwidth follow the instructions
1)Open "run" and type "gpedit.msc"
2)It will open Group Policy editor window
3)There select Computer configuration
4)Select Administrative Templates
5)Select Network
6)Select QoS Packet Scheduler
7)There select "Limit Reservable Bandwidth"
8)It will open a New window
9)By default It would b set to "not configured"
10)Click on "enabled" and change 20 to 0
11)Then apply the settings...
Now you will have full utilisation of your bandwidth.
